Gravel bars are characteristic components of river landscapes and are increasingly recognized as key sites for many waterbirds, though detailed studies on the ecological function of gravel bars for waterbirds are rare. In this study, we surveyed the endangered Scaly-sided Merganser Mergus squamatus along a 40 km river section of Yuan River, in Central China, for three consecutive winters. We de...

t The effect of sesquioxidic i i ic gravels (>2 mm size fraction) on phosphorus sorption by two gravelly lateritic soils was investigated by phosphorus sorption experiments, X-ray diffraction, ti , autoradiography and electron microscopy. In one soil the abundance and size of gravels l decreased downslope. As the gravel content of both soils increased (13-61%), ), the proportion of large (>8 mm...

Mountainous river beds-generally consist of gravel particles that the precise description of such bed is not only important hydraulically, but also it has great environmental significance. The accurate estimation of bed roughness gives us valuable information to make reliable hydraulic models of flow in river with rigorous bed form. This study discuses about the accuracy of the Kinect device in...

Through the laboratory experiments, the mechanical properties of sandy gravel are obtained. Then, based on the slump tests, a modified sandy gravel model is developed by PFC (particle flow code of three dimensions), to which relevant microscopic parameters are assigned to numerically simulate the laboratory experiments. The laboratory test results are compared with that of the numerical simulat...

this paper presents a model for prediction of the mechanical behavior of sand-gravel mixtures using generalized plasticity and critical state concepts. proposed model is based on the difference between critical state lines of sand and sand-gravel mixture in e-lnp' plane. a generalized plasticity model is considered as the base model for sandy soil. its state parameter, dilation rate and ha...

there are limitations in experimental studies on sand-gravel mixtures due to the small size of testingspecimens. due to this problem, many researchers have worked on prediction of the shear strength of mixture by testingthe sandy fraction of soil alone and developed empirical relationships. most of the previous relationships have beendetermined for low surcharge pressures in which particle brea...

Rivers sourced in the Himalayan mountain range carry some of the largest sediment loads on the planet, yet coarse gravel in these rivers vanishes within approximately 10-40 kilometres on entering the Ganga Plain (the part of the North Indian River Plain containing the Ganges River). Understanding the fate of gravel is important for forecasting the response of rivers to large influxes of sedimen...

Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the...

Laboratory studies were conducted to investigate scrap-tire-shreds as a potential alternative to conventional gravel in the drainage layer of leachate collection system at the base of landfill. Performance of various physico-chemical characteristics of leachate after passing it through combined bed of scrap-tire-shreds and gravel for different combinations of thickness of scrap-tireshreds and g...